1 TPlite is Back! Jim Gray Microsoft Research High Performance Transaction Processing Workshop, Asilomar, CA., 27 September 2005,

2 Summary Statement Database system’s have changed –Is a web service (listens to port 80, does wsdl+soap,…) –Hosts a programming environment (J2EE VM or.NET CLR or… ) So, Client-Server (a.k.a. tplite) –is possible –Has always been easier than 3-tier.

3 Outline History: Everyone Went to 3-tier (and why) New news (DB + Languages + WS-*): –Extensible DBs have arrived. –Full blown programming environment inside –Fewer technologies: DB integrated with language. Web service integrated with class/method. Fears –DMZ and attack surface.

4 Work Distribution Spectrum Presentation and plug-ins Workflow manages session & invokes objects Application Objects Database Fat Thin Fat Thin Database App Objects workflows Presentation

5 Transaction Processing Evolution to 3 Tier Mainframe Batch processing (centralized) Dumb terminals & Remote Job Entry Intelligent terminals database backends Workflow Systems Object Request Brokers Application Generators Mainframe cards Active green screen 3270 Server TP Monitor ORB

6 PC Evolution to Three Tier Stand-alone PC (centralized) PC + File & print server message per I/O PC + Database server message per SQL statement PC + App server message per transaction ActiveX Client, ORB ActiveX server, Xscript disk I/O IO request reply SQL Statement Transaction

7 Web Evolution to Three Tier Character-mode clients, smart servers GUI Browsers - Web file servers GUI Plugins - Web dispatchers - CGI Smart clients - Web dispatcher (ORB) pools of app servers (ISAPI, Viper) workflow scripts at client & server archie ghopher green screen Web Server Mosaic WAIS DHTML AJAX

8 The Pattern: Three Tier Computing Clients do presentation, gather input Clients do some workflow (Xscript) Clients send high-level requests to ORB ORB dispatches workflows Server-side workflow scripts orchestrate distributed App objects State stored in DB Database App Objects workflow Presentation

9 Why Did Everyone Go To Three-Tier? Manageability –App rules must be with data –Middleware operations tools Performance (scalability) –Server resources are precious –ORB dispatches requests to server pools –DBMS was DREADFUL at connections Connection pools Technology & Physics –Put UI processing near user –Put shared data processing near shared data Database AppObjects workflow Presentation

10 Multiplexing DB client connection: –Mega-instruction set up –Mega-byte state TP mon or Web Server or ORB –Lightweight connection setup –Multiplex many clients to few DB connections (connection pool) –Act as ORB (manage & dispatch server pools). –Act as object container. ORBDB

11 Complexity: Dark Side of 3-Tier 3 programming environments Lots of configuration choices Lots of interface problems SQL, PL/SQL, T-SQL, … in DB It isn’t simple!!

12 Outline History: Everyone Went to 3-tier (and why) New news (DB + Languages + WS-*): –Extensible DBs have arrived. –Full blown programming environment inside –Fewer technologies: DB integrated with language. Web service integrated with class/method. Fears –DMZ and attack surface.

13 DB Systems Get VMs DB has language VM execution environment Language guys are “embracing” DB Class is a web service: Generate WSDL VERY simple –programming –debugging Fewer languages & Tools to learn See SQLJ or LINQ or… EJB Network Thread Pool Queue Connections Context Security Shared Data Receiver Service logic Configuration Management A Server

14 The New World – Programs + Data It finally happened –Languages have sets (lists, dictionaries, …) –Table inherits from iEnumerable List E = new Employee(); for each e in E {} –Rows are objects –Query answers are collections –Supports transactions –Push a button and you have a web service.

15 SqlConnection c = new SqlConnection(…); c.Open(); SqlCommand cmd = new c.Name, c.Phone FROM Customers c WHERE c.City ); = “London”; DataReader dr = c.Execute(cmd); while (dr.Read()) { string name = r.GetString(0); string phone = r.GetString(1); DateTime date = r.GetDateTime(2); } r.Close(); Old Data Access in API’s Queries in quotes Arguments loosely bound Results loosely typed Compiler cannot help catch mistakes

16 Integrated Data Access public class Customer { public class Customer { public int Id; public int Id; public string Name; public string Name; public string Phone; public string Phone; … } Table customers = …; Table customers = …; foreach(c in customers.Where(City == “London”)) { foreach(c in customers.Where(City == “London”)) { Console.WriteLine(“Name: {0} Phone: {1}”, c.Name, c.Phone ); Console.WriteLine(“Name: {0} Phone: {1}”, c.Name, c.Phone );} Classes describe data Tables are real objects Query is natural part of the language Results are strongly typed

17 Web Services Now trivial to publish your data. Just say: “Make this method a web service.” Everything else is automatic Performance is easy to understand –Simplest configuration –Simplest management Minimal data movement Fewest round trips.

18 DBs are Federating So Now Do Connection Management DB needs to –talk to peers scaleout –Talk to foreigners data integration So, it is a client for multiplexing & connection pooling So, now they get it, (they finally had to write an app) and they are doing it. So, DB now does multiplexing DBClient Other Data Sources us Foreigners

19 Outline History: Everyone Went to 3-tier (and why) New news (DB + Languages + WS-*): –Extensible DBs have arrived. –Full blown programming environment inside –Fewer technologies: DB integrated with language. Web service integrated with class/method. Fears –DMZ and attack surface.

20 Fears DB has large attack surface Web servers act as DMZ to Internet. Premise: –We can lock-down the DBMS interfaces –Only show “public” web services to outside.

21 Summary Statement Database system’s have changed –Is a web service (listens to port 80, does wsdl+soap,…) –Hosts a programming environment (J2EE VM or.NET CLR or… ) So, Client-Server (a.k.a. TPlite) –is possible –Has always been easier than 3-tier. –Integration of DB and Language makes it VERY natural